Keep an eye on your shop's waste

Don’t let material pile up. Unprocessed scrap takes up space and should be processed in-house, when necessary.

How a metalworking operation handles hazardous waste management and disposal obviously has a big impact on the environment. But it also directly influences its profitability.

Failed inspections, fines, inefficient operations, risks to employee health and safety, as well as environmental contamination are among the consequences of improper hazardous waste handling. Because regulations change periodically, it is critical to re-evaluate and consider improvements to hazardous waste management practices on a semi-regular basis. In addition, updating hazardous waste processes can result in more efficient labour allocation, enhance housekeeping efforts, and leverage more sustainable revenue sources.

To identify possible areas for improvement, consider asking these four questions:

1. Is metal scrap being removed from the shop floor in a manner that eliminates or limits unsafe manual labour?
2. Is the floor space in my plant getting overcrowded by metal scrap and fluid storage receptacles, impacting workplace safety and productivity?
3. Is the amount of fluid waste or the volume of scrap metal contributing to high haul-away or fluid replacement costs?
4. Could further in-house processing of hazardous metal scrap and fluid improve compliance and provide opportunities for more long-term cost savings?

What Waste Is Considered Hazardous?

Hazardous waste common to manufacturing processes includes spent solvents, electroplating fluids, and metalworking waste products. Depending on the type and amount of waste, there are specific rules that must be followed regarding handling and disposal.

Some common hazardous fluid waste in metalworking operations are:

• Solvents and degreasers
• Cutting fluids
• Lubricants
• Paint
• Wastewater pretreatment sludge

In metalworking operations, fluid-coated metal scrap complicates hazardous waste compliance because it adds to the overall volume of hazardous material and increases labour costs, haul-away fees, and the expense of replacing spent fluid.

Metal waste such as swarf, shavings, and grinding fines also can be hazardous depending on the type of metal and cooling lubricant used.

Generally speaking, two methods – separating cutting fluid from metal scrap and prolonging fluid life with filtration technology – can be employed to improve hazardous waste compliance and handling. Both processes have been proven to be very effective, and several automated equipment options are available.

The Drier, the Better

The drier the metal scrap, the higher its value is to recyclers. In some cases, metalworking operations can receive up to 25 per cent more for dry metal scrap than scrap that is still coated in fluid. Using processes that separate and reduce the volume of scrap material and cutting fluid also helps keep facilities clean because it reduces the amount of space and containers needed for storage on the plant floor. There are several machine options to do this.

Wringers and industrial centrifuges use centrifugal force to spin fluid and remove moisture from metal chips. This allows for up to 98 per cent reclamation of cutting fluid that can then be recycled and reused to reduce the need and added expense of buying replacement fluid. A variety of metals including aluminum, brass, cast iron, steel, and stainless steel can be processed using this equipment.

Many industrial options exist for handling your shop’s chips and coolant.

Crushers help to reduce the volume of large bundles of metal turnings into flowable, thumbnail-size chips. Crushers can be used as stand-alone units or as part of a larger system with either horizontal or vertical orientation.

Shredders make it easy to turn light-to-moderate metal turnings into flowable chips and can be applied to reduce the volume of metal turnings by up to four times, further increasing the metal scrap value for the recycler.

Tramp metal separators should be used to protect the process equipment from damage. This equipment removes bar ends, broken tooling, and other metal solids from chip flow.

Extend Fluid Life

Another tactic that can be employed to better manage hazardous fluid is using fluid filtration equipment. These systems reduce hazardous waste volumes by as much as 90 per cent and lower new fluid purchases by 75 per cent. Employee health and safety also are improved by minimizing bacteria levels in cutting fluid, which can help prevent dermatitis.

Centralized coolant recycling systems automatically recycle used coolants, reducing waste fluids up to 90 per cent. These systems can also remove free-floating tramp oils to 0.1 per cent or less, eliminating concerns about wastewater haul-away liabilities and minimizing exposure to lubricants that can cause health problems.

Tramp oil separators cut new coolant purchases by up to 75 per cent by extending the life of soluble oils, coolant, and washwater. Tramp oil separators automatically remove tramp oils, bacteria, slime, and inverted emulsions from individual machine sumps, central systems, and wash tanks.

A metalworking facility with in-house processes that address the ongoing environmental and safety concerns of hazardous waste first and foremost is essential to the health of all staff. However, by adding automated equipment to handle hazardous waste, shop owners also benefit from lowered labour, fluid, and haul-away costs and possibly securing a higher price from metal scrap recyclers.

Improving hazardous waste handling practices such as these provides a way to take greater control of compliance concerns and encourages more sustainable savings that will benefit the operation year after year.

Mike Hook is sales and marketing director for PRAB, 5801 E. N Ave., Kalamazoo, Mich. 49048, 800-968-7722, www.prab.com.

Fluid-coated metal scrap complicates hazardous waste compliance because it adds to the overall volume of hazardous material and increases labour costs, haul-away fees, and the expense of replacing spent fluid.